A method for forming a string of memory cells, a memory device having a string of memory cells, and a system are disclosed. The string of memory cells can include a string of planar memory cells formed as recesses in each of a plurality of control gate material formed as a vertical stack of alternating insulator and control gate material. The recesses can be lined with a dielectric material and filled with a floating gate material. Metal nano-particles can be formed on a surface of the floating gate material and/or infused into the floating gate material.